Split Focus Ring Assembly for Uniform Wafer Edge Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, the etching process in semiconductor reaction chambers faces challenges with poor etching uniformity due to the reduction in focus ring thickness, leading to increased edge etching rates, and safety concerns from displacement and potential fall-off of the focus ring during compensation mechanisms.
Innovation Solution
A carrier device with a split focus ring assembly, including a lower and upper focus ring, where the upper focus ring ascends within a groove on the lower focus ring, supported by position-limiting members, and focus ring thimbles that lift the upper focus ring to maintain etching uniformity without affecting wafer absorption or position precision, and prevent displacement and falling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the focus ring is lifted by a thimble driven by a driving mechanism to compensate for etched areas, then etching uniformity is improved, but the position of the focus ring on the thimble is displaced, affecting absorption and position precision of the wafer
Solution Approach 1:
The focus ring assembly is divided into an upper focus ring and a lower focus ring that are movable relative to each other. The upper focus ring can be independently lifted by thimbles while the lower focus ring remains stationary, allowing compensation for etched areas without displacing the entire focus ring assembly and thus maintaining wafer position precision.
Solution Approach 2:
The lower focus ring acts as an intermediary structure that remains stationary while the upper focus ring moves independently. This separation allows the upper focus ring to compensate for etching wear without affecting the overall position of the focus ring assembly relative to the wafer, thereby maintaining both etching uniformity and position precision.
2Manufacturing precision
If the focus ring is subjected to a push force of the thimble when the thimble lifts the focus ring up, then the focus ring can be raised to compensate for etching, but the focus ring may easily fall off from the thimble, reducing safety
Solution Approach 1:
The focus ring is segmented into upper and lower parts that can move independently. The upper focus ring is lifted by thimbles while the lower focus ring remains fixed, providing a stable base that prevents the focus ring from falling off during the lifting process, thus improving safety while maintaining etching uniformity.
Solution Approach 2:
The lower focus ring serves as a pre-positioned support structure that remains stationary during the lifting process. This beforehand cushioning prevents the upper focus ring from falling off the thimbles by providing a stable reference structure, thereby improving the reliability and safety of the semiconductor reaction chamber.
3Manufacturing precision
If the focus ring is lifted to compensate for etched areas, then etching uniformity is improved, but the structure becomes more complex with multiple movable parts
Solution Approach 1:
The focus ring assembly is segmented into upper and lower focus rings with independent movement capabilities. This segmentation allows the upper focus ring to be lifted independently by thimbles for compensation while the lower focus ring remains stationary, achieving etching uniformity without requiring complex multi-part movable structures.
Solution Approach 2:
The focus ring assembly employs dynamic characteristics by allowing the upper focus ring to move vertically relative to the lower focus ring. This dynamic design enables compensation for etching wear through simple vertical movement of the upper ring, avoiding the need for complex mechanical structures while maintaining etching uniformity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures etching uniformity by compensating for etched areas without affecting wafer position precision and improves safety by stabilizing the focus ring, reducing the risk of displacement and falling, thus enhancing the semiconductor reaction chamber's safety and efficiency.
Implementation Method 1
an electrostatic chuck and a focus ring are arranged in the semiconductor reaction chamber of the etching machine. The electrostatic chuck is configured to support the wafer.
Data Source
AI summary
A carrier device is configured to carry a wafer in a semiconductor reaction chamber. The carrier device includes a chuck, a focus ring assembly, and a plurality of focus ring thimbles. The chuck is arranged in the semiconductor reaction chamber to support the wafer. The focus ring assembly includes a lower focus ring and an upper focus ring. The lower focus ring is arranged around the chuck. The lower focus ring includes a groove on an upper surface of the lower focus ring. A part of an upper surface of the lower focus ring located on an inner side of the groove is a support area. A first position-limiting member is arranged on a lower surface of the upper focus ring and corresponds to the groove. The plurality of focus ring thimbles are distributed along a circumference of the upper focus ring at intervals.